Foam reservoir fluid transfer roller

Abstract

A fluid transfer roller for use in offset printing for picking up a film of water and transferring it to a printing plate consists of a rigid core with an outer layer of foamed-in-place, partially open-celled foam.

We claim: 
     
       1. A fluid transfer roller for use in an offset printing press; said improved dampening roller comprising: (a) a rigid core; and,   (b) an integral, foamed-in-place, cellular foam outer layer on said core, said foam having a compressibility of about 5 to about 100 psi as measured by ASTM D575-91 and containing about 10% to about 90% open cells at least some of which are interconnected.   
     
     
       2. A fluid transfer roller of claim 1 in which the foam is of polyurethane. 
     
     
       3. A fluid transfer roller for use in an offset printing press for picking up a film of water and transferring it to the plate cylinder, said improved roller comprising: (a) a rigid core; and,   (b) an outer layer of foamed-in-place, cellular foam, said foam having a free flow density of about 5 to about 70 pcf and a thickness of about 0.025" to about 0.250".   
     
     
       4. The fluid transfer roller of claim 3 in which the foam is of polyurethane. 
     
     
       5. The fluid transfer roller of claim 3 in which there is an intermediate layer of elastomeric material between the core and the outer layer. 
     
     
       6. The fluid transfer roller of claim 5 in which the intermediate layer is of polyurethane.